In August 2019 the Moon has fascinated with its brightness and its conjunctions, and has had 5 phases instead of the usual 4. On 9, 10 and 11 August, our natural satellite, in full swing phase, danced with Jupiter and Saturn, and then stole the scene during the period of visibility of the meteor shower of the Perseids, better known as the “Tears of St. Lorenzo”.
The maximum of the phenomenon this year was in the night between 12 and 13 August, but the observation was complicated precisely by the presence of the Moon, which was Fullin August.
In August 2019, two particularly interesting phases of the moon are scheduled: the Moon of the Sturgeon and the Black Moon. The August 1st the moon was new, on August 7 was in First Quarter, while the 15 August shone the full moon “of Sturgeon” (a name chosen by the tribe of the Algonquian, American Indians).
The satellite was at the Last Quarter on August 23, and finally 30 is New Moon.
On the 30th the second New Moon of the month rises , which is nicknamed Black Moon. No bad omen, it is only a new moon.
Usually every month there is a Full Moon and a New Moon: sometimes it may happen that a second Full Moon occurs in the same month, which is nicknamed Blue Moon, or Blue Moon, or a second New Moon, which is called, precisely Black Moon (keep in mind that these are “folkloristic” terms, they are not used in astronomy).
Since it is therefore a new moon, our satellite, although high in the sky, will not be visible. Our satellite found itself at the perigee , at the point closest to the Earth along its orbit , on 2 (359397 km), at the opposite point on 17 (apogee, 406243 km) and again at perigee on 30 (357175 km).
Consequently, the Black Moon and the perigee will coincide: it will therefore be a Supermoon, which being in the phase of the new moon is certainly more difficult to appreciate, but still a very rare and fascinating event.
If the Moon traveled a perfectly circular orbit around the Earth, its distance from our planet would be constant, as would the apparent diameter of the Moon. However, since the Moon goes through an elliptical orbit, it follows that it will not always be at the same distance from the Earth, but at a variable distance between a minimum value (perigee) to about 356.410 km, and a maximum value (apogee) to about 406,740 km.
At the apogee the Moon appears slightly smaller than when it is at the perigee.
The difference between the maximum and minimum points is about 50,000 kilometers, enough to make it appear on average 14% larger and 30% brighter than the perigee. This is a normal phenomenon due to the fact that the Moon is at the minimum distance from the Earth, a cyclical phenomenon and not rare but still suggestive.
The term Supermoon, coined by Richard Nolle (astrologer), simply indicates the lunar perigee from the scientific point of view. Nolle defined the Supermoon as a “new moon or full moon that occurs when the Moon is at or near (within 90% of) the point of minimum distance from the Earth in a given orbit,” (ie 361,836 km away) so, according to this definition, they occur between 4 and 6 Supermoon each year on average.